Coupling of shafting fob propellers



UTTED i sTATEs PATENT onirica.

S. WILMARTH, OF CHARLESTOWN, S. L. HAY, OF 'RADINCL AND D. N. B. COFFIN,JRaOF NEWTON, MASSACHUSETTS.

COUPLING OF SHAFTING FOR PROPELLERS.

Specification of Letters Patent .Na-19,887, dated April 6, 1858.

To all whom it 'may concern:

Be it known that we, SETH WILMARTH, of Charlestown, SAMUEL L. HAY, ofRea-ding, and DAVID N B. COFFIN, J r., of Newton, all in the county ofMiddlesex and State of Massachusetts, have invented certain Improvementsinl Couplings for Shafting; and we do hereby declare that-the followingis a full, clear, and exact description of the same, referencebeing hadto the accompanying drawings, which form a part of this speciication,and to the letters of reference marked thereon.

Explanation 0fcZmwz'ngs.-Figure 1 is a side elevation of the couplingrepresented as coupling together the adjacent ends of two pieces ofshafting lettered respectively a and o, with sectional view of theirbearings.-

Fig. 2 is a section of head plate h, which is keyed in the ordinarymanner to a, and shows a side view ofthe screw or pin c. Fig. 3 issimply an end eleva-tion of one half of one of the bearings. Fig.l 4 isa view of the right hand side of the middlel plate d. Fig. 5 is a viewof the face of head plate e. Fig. 6 is a plan of themiddle plate d. Fig.7 is a section through plate CZ, on line f, g. Fig. S is a view of theface of head plate h. Fig. 9 is a side elevation of one of the variousmodifications of our improved coupling which may be made, this beingbetter adapted to use in the rough casting perhaps than the other shownin Fig. 1. Fig. 10 is a plan of middle plate lc. Fig. 11 is a section ofthe same at line Z, m. Fig. 12 is a view of the right hand side ofmiddleplate 7c. Fig. 13 is a view of thevface of head plate z'. Fig. 14is a view of the face of head plate J. i

Like letters indicate the same part in all the gures.

The object of this invention is to provide for both the angular and thetransverse variation at the joints of shafting particularly of propellershaft-s in steam vessels. By angular variation we mean the deviation ofthe shaft from a direct line when the axes coincide at the joint. Bytransverse variat-ion we mean the want of coincidence of the axes of thetwo parts of the shaft at the joint.

Steam vessels are notperfectly rigid but must and do on account of theirextreme length yield by their tendency to accommodate themselves to theswells through and over which they pass. This of course throws theshafting out of a. direct line and causes both the above variations totake place. Now although the common universal joint will provide for theangular, it will not Vprovide for the transverse variation, andtherefore, as is the case with most and as we believe all other knowncouplings, wi'll cause an immense strain both on-themselves and on thebearings of the shaft and will also `cause the bearings to wear and cutbadly. Now our improvement proposes to provide for both of thesevariations by a very simple and inexpensive combination of parts,whether the variation be changeable or permanent.

That others skilled in the arts to which our invention pertains may beable to make and use our improvement we will proceed to describe theconstruction and operation of the same.

We'provide each of the two ends of the shafting to be coupled togetherwith a circular plate of proper diameter and of suitable thickness forstrength. See e, Fig. 1. This plate has a hub g, into which the end ofthe shaftis fitted and keyed in the usual manner. Across the face ofeach plate is arranged a tongue as 0 and 79, Fig. 1. The surfaces ofthis tongue are made smooth so as to allow the part operating upon it toslide freely. They may also be hardened. A plate d, corresponding insize to h and e, has a groove upon each of its opposite sides fitted toslide one upon the tongue 0 and the other upon the tongue p. Thesegrooves are formed at right angles with each other. The tongues o and p,may be permanently fast to the head plates 71, ande, or one of them maybe made 'removable for convenience of uncoupling, as shown in Fig. 1,

Fig. 2, &c., the tongue 70, being slid into a T-shaped groove in thehead plate and kept from sliding out by the screw or pin c. See Figs. 1,2, and 8. The middle plate d, has its faces beveled oft' from near thecenter each way to the periphery at theends of the grooves, as shown,and the grooves are made of equal depth from these beveled surfaces andthe surface at the middle. These bevels however are not essentials, asthe surfaces may he made straight and parallel, or curved and yet answerthe purpose.

When it is desired to couple the shafts not already in the bearings, onepart of the into the other groove in CZ, after Which, the

caps being screwed on to the bearings, the Whole is ready to operate.NOW by reason of the grooves in al, being arranged at right angles Witheach other and the tongues Working freely in the grooves, one part ofthe shaft, b, for instance, may be moved to the right, or left, or up,or down, out of the line of part a, and yet Y), and a, be made torevolve freely together, b, being driven bya a, or a, by b. This is alsothe case When the two parts of the shaft are placed at an angle witheach other, their aXes coinciding at the coupling or otherwise. Theseoperations may be understood by reference to the drawings, as thebearing opposite the end Which receives the crank is susceptible ofbeing moved to the right or left or swiveled either permanently orvariably during the operation by suitably tightening or loosening thescrew underneath, by Which it is held, and turning the crank with andduring these variations. The above result is produced through theswiveling and sliding of plate d, upon the tongues p and o.

When it is desirable to uncouple and disconnect the t-Wo parts of theshaft, as is sometimes the case With propeller shafts for steam vessels,Without removing them from their bearings, it is simply necessary totake out the screw or pin c, When the tongue p, can be slid freely out,after Which plat-e d, Will slide out freely and the parts of the shaftbe entirely disconnected. The tongues can of course be made on CZ, andgrooves in the other plates, but Wel prefer the described method.

The modication illustrated by Fig. 9, and details in Figs. 10, 11, l2,13, and lll, is the same in its most essential features. The principaldifference is that the tongues and grooves are not continuous across thefaces of the plates, and being formed permanently in and upon them theshaft cannot so readily be uncoupled in the use of them. In this form agood coupling can be made for many purposes by casting simply, with onlythe exception of boring and keying to the shaft. I

Having thus described our improvements What We claim as our inventionand desire to secure by Letters Patent is as follows:

We claim the combination of plate cl, or its equivalent With the headplates of the shaft in any manner substantially as described so thatthecoupling may accommodate itself to the angular and transverse variationbetween the driving and driven parts of the shaft Whether that variationbe variable or permanent.

Witnesses:

P. A. J. DUNBAR, SAML. F. HAY.

